Nowadays, substractive three primary colors are employed for a silver halide color photographic light-sensitive material. A color image is formed by the combination of three dyes formed by a coupling reaction between couplers, i.e., a yellow coupler, a magenta coupler, a cyan coupler, and an oxidized p-phenylenediamine-based color developing agent.
As a magenta coupler for a silver halide color photographic light-sensitive material, pyrazolone, pyrazolinobenzimidazole, pyrazolonetriazole and indanone have heretofore been employed in the industry. Of them, 5-pyrazolone derivatives are the most common.
Examples of 5-pyrazolone derivatives include those obtained by introducing into the 3-position of 5-pyrazolone an alkyl group; aryl group; an alkoxy group (see U.S. Pat. No. 2,439,098); an acylamino group (see U.S. Pat. Nos. 2,369,489 and 2,600,788); and a ureido group (see U.S. Pat. No. 3,558,319).
These conventional magenta couplers, however, have a defect that does not allow a high-density magenta dye image to be obtained due to their low coupling activity. Further, a magenta dye produced from these couplers has an unfavorable secondary absorption in the blue light region, and its primary absorption is not sharp-cut in the longer wavelength region.
A 3-anilino-5-pyrazolone-based coupler described in U.S. Pat. No. 2,311,081, 3,677,764, British Patent Nos. 956,261 and 1,173,513 is improved in coupling activity and color development, and capable of providing a dye which has a very small secondary absorption in the red light region. However, this coupler has such a disadvantage that a dye formed therefrom has a primary absorption in a relatively short wavelength region, and, hence, a color negative film produced by using this coupler has poor color reproducibility.
Meanwhile, it has been revealed that, when a color negative is printed on color paper to obtain a photographic print, the hue of the photographic print tends to vary according to the type of printer employed. The hue of a magenta coupler contained in a negative is one of the factors contributing to this phenomenon.
It should be noted that such a variation in hue is most serious when a 3-anilino-5-pyrazolone-based coupler is employed as a magenta coupler.
Variation in photoprint hue caused by a change in the type of a printer can be suppressed to some extent by the use of a magenta coupler described in Japanese Patent Examined Publication No. 30615/1980.
However, studies by the inventors have revealed that this magenta coupler causes fogging, and makes the photographic properties of a light-sensitive material deteriorate during storage by the action of a harmful substance such as formaldehyde.